MADISON, Wis. (Reuters) - Close to 2,000 students marched in Wisconsin’s capital on Monday to protest the fatal police shooting of an unarmed biracial teenager, while his family demanded justice and the police chief apologized.

Candles are piled in the snow outside the home of Tony Robinson Jr. during a candlelight vigil on Williamson Street in Madison, Wisconsin March 8, 2015. REUTERS/Ben Brewer

Students crowded into the rotunda of the state Capitol in the morning, chanting and waving signs to protest the death of Tony Robinson, 19, shot on Friday by a white police officer.

Later, Turin Carter, Robinson’s uncle, said his family was calling for a thorough investigation and was concerned about the “systematic targeting of young black males,” but did not endorse blanket anti-police sentiments.

“We are not proponents of anti-police (attitudes)... We understand that law enforcement is necessary and mandatory and we need to change our mindset about the police,” Carter said at a news conference outside the house where Robinson was shot.

Standing near a memorial of candles and balloons, Carter said it was simplistic to call Robinson African American, saying he had a mixed heritage and his racial ambiguity was a central issue in his life.

Police shootings across the country have intensified concerns of racial bias in law enforcement.

Many teenagers at the morning protests were from Robinson’s alma mater, Sun Prairie High School.

“There is an indifference between people and police. We all need to come together,” said Ali Asafford, 15, after leaving class at Madison’s East High School. The march was orderly and police presence was minimal.

Officer Matt Kenny, the 12-year police veteran who shot Robinson, is on paid administrative leave while the Wisconsin Department of Justice investigates the shooting. In 2007, Kenny was involved in a fatal shooting that was found to be justified.

Police Chief Michael Koval apologized on Monday after praying with Robinson’s grandmother over the weekend and pledging transparency in the investigation.

“Reconciliation cannot begin without my stating ‘I am sorry,’ and I don’t think I can say this enough. I am sorry. I hope that, with time, Tony’s family and friends can search their hearts to render some measure of forgiveness,” Koval wrote in his blog.

Attorney General Brad Schimel asked the public to be patient with the investigation, saying his office would not be able to disclose details since it could taint testimony from witnesses.

Official efforts to be transparent, apologetic and light-handed with protesters followed months of heightened attention to police use of deadly force across the United States.

Last year, the police shooting death of black teenager Michael Brown in Ferguson, Missouri, set off weeks of protests that sometimes turned violent. Police reaction was criticized as heavy-handed, and critics were outraged at the long delay in releasing the name of the officer who shot Brown.

Madison, a city of 240,000 people about 80 miles (130 km) west of Milwaukee, has a mostly white population. The city is 7 percent African-American, U.S. Census figures show.

On Friday night, Kenny, 45, responded to reports of an assault and a man dodging cars in traffic. Kenny followed the suspect into a dwelling. Koval said the officer was struck in the head and then shot the unarmed teen.

Last year, Robinson pleaded guilty to armed robbery, and was placed on probation. Sentencing documents show it was his first brush with the law, and he was not the armed person in the group that committed the robbery.

Concern about Wisconsin’s own history of police use of deadly force prompted passage of a law last year requiring independent investigators to probe such incidents. The bill had support from police associations.

The head of the local NAACP chapter said the Madison police department did not engage in the sort of racial targeting that the U.S. Justice Department found prevalent in Ferguson.

“I have observed what I think is a very effective community policing structure, and I think it makes a difference,” said Greg Jones, president of the Dane County chapter of the advocacy group.