The weeklong investigation into the after-school disappearance of a 10-year-old Crystal boy pivoted abruptly Thursday to an area of the Mississippi River south of Interstate 694.

Crystal Police Chief Stephanie Revering said that Barway Collins’ father, Pierre Collins, remains the primary suspect in his son’s disappearance and that investigators now believe he was near the river just after the boy was last seen about 4:15 p.m. on March 18.

“Based on our investigation, we now know that Pierre Collins was in the area of the Mississippi River … shortly after Barway’s disappearance,” Revering said at a late-afternoon news conference. “… We have strong evidence.”

Collins, who has not been arrested or charged, “continues to not be truthful” with investigators, she said.

The boy’s father has said repeatedly that he had nothing to do with his son’s disappearance.

Revering said that investigators also believe a second person might have been involved in Barway’s disappearance, but declined to offer details. She said the investigation centers on an area east of Crystal from I-694 south to Minneapolis’ Webber-Camden area, along the Mississippi River. However, she did not describe any active searches.

She issued an appeal for any video footage from businesses or individuals from the area from the afternoon of March 18.

Crystal police are offering a $12,000 reward for information leading to an arrest and prosecution.

Pierre Collins’ phone number appeared to have been changed or disconnected Thursday, and he did not answer the doorbell at his apartment building.

Interviewed in his Crystal apartment Wednesday, the 33-year-old man said he done everything he can to help police find his son. “I’ve been working with the police just to bring my son home,” he said then, frequently breaking into tears as he spoke.

His wife, Yamah Collins, said she noticed Barway was missing at 5 p.m. and called her husband, who was not home. She said Pierre then called the school van service, which told him Barway was dropped off. The family began searching nearby parks and called family members, she said.

A camera in the school van recorded Barway hopping out after casually telling a friend that he saw his “dad,” then his “uncle.”

When asked on the “Nancy Grace” TV show who the “uncle” is, Pierre Collins said he didn’t know.

Barway Collins’ birth mother, Mami Momo, who lives in Liberia, was in shock when she heard about his disappearance, Pierre Collins said Wednesday.

Public records show no criminal record beyond traffic and fishing fines for Collins, who legally changed his name to Pierre Barlee Collins from Barlee Smith in 2008.

In early 2013, Jennifer Beaver, an ex-wife of Pierre Collins who now lives in Wisconsin, filed an order-for-protection petition against him, public records show. The two, who were married for about 3½ years, divorced later in 2013.

In the order-for-protection documents, she alleges that Pierre abused her and their children. Under the order of protection, which expired March 14, he was not to visit his children’s schools. Barway, who emigrated to the United States from Liberia in 2011 with his father, is a fourth-grader at Evergreen Park World Cultures Community School, where Principal Sheryl Ray said he is well-liked and much-missed.