Angel Valdivia, 19, was stabbed during a fight at Seccombe Lake Park in San Bernardino on June 5, 2016, and died. Two other people were wounded.

A fight with three people stabbed in a public park means there were a lot of people around, and some of them know who had the knife. San Bernardino police have asked for help, but witnesses haven't come forward.

If you were at Seccombe Lake that day or knew Angel, San Bernardino police or WeTip will take your information anonymously.